That would depend on if you tested yourself using the first urination of the day (when THCA levels would be at their highest and unaffected by any fluid consumption that would occur during the normal course of the day).

If you tested negative with the first urination of the day, youre good to go.

If you dont hear anything from the employer by Thursday, call up and ask for your 'start date'. The employers response there would shed light on whether you did pass, or if the employer had simply moved on to the next applicant for hire.
Never inquire about the test results. A person who is truly drug-free would never do this because, being clean, theres no reason to do so. Doing so would only raise eyebrows and make things look bad for you if you want to be viewed as a "drug-free person".
If a start date has already been secured, then simply show up for the first day and carry on with your duties in a manner that a drug-free person would.